Ultrasound of the Hook of Hamate Region: Pictorial Review

The hook of hamate is a complex anatomical region with many small but important structures. A sound knowledge of anatomy along with a systematic ultrasound technique can help delineate a variety of disorders. In this pictorial review, we discuss the ultrasound anatomy and the possible pathologies that can be encountered in this region.

Arthroscopic Excision of Hamate Osteoid Osteoma

Osteoid osteoma is considered the most common benign bone forming tumor accounting for 12% of all benign bone tumors. The carpus is a rare site for this tumor but quite a few cases were reported before. The lesion can be subperiosteal, cortical or medullary. Computed tomography scan is the gold standard diagnostic study, whereas magnetic resonance imaging can result in delaying the diagnosis as reported in the literature. Open excision with or without grafting was the technique of choice in most reviewed cases in the literature. In this paper we will illustrate a minimally invasive technique using wrist arthroscopy for an osteoid osteoma of hamate proximal pole. This minimally invasive arthroscopic technique provides a rapid recovery for patients with lesions that are accessible to wrist arthroscopy.

Hook of Hamate Fractures

Hook of hamate fractures are uncommon injuries with unclear prevalence. Classic presenting symptoms include volar-ulnar hand/wrist pain and weakness in grip, with possible ulnar nerve paresthesias. Patient factors, such as activity level and desired return to work/sport, shape the most appropriate treatment regimen although excision of the hook has been adopted by most surgeons. Overall, once patients receive the correct diagnosis and are treated, good outcomes with high satisfaction rates are expected.

First reported case of a coronal hamate fracture associated with intrusion of the fifth metacarpal base, together with a fracture of the fourth metacarpal base

We present a case reporting a rare combination of base of fourth metacarpal fracture and coronal body of hamate fracture, treated conservatively with excellent results. High index of suspicion for undetected bony injuries drove the execution of a CT scan, which allowed us to make a full correct diagnosis and plan treatment. Moreover, this case becomes the first reported case in the literature of such injury causing the intrusion of the base of the fifth metacarpal within the hamate bone, thus causing the coronal pattern of the hamate fracture. Differently from the common surgical management of this type of injury, we successfully treated this patient with close reduction and immobilisation, with full recovery after 3 months.

Unsuccessful Intervention of CT-Assisted Osteosynthesis for Stress Fractures of the Hook of the Hamate: A Report of 3 Cases

CASE

We performed computed tomography (CT)-assisted dorsal approach osteosynthesis for stress fractures of the hook of the hamate using the dorsal approach in 3 high school baseball players in the hybrid operating room. Bony union was observed in all patients on CT. All patients were able to play baseball without pain for at least 6 months after surgery. However, refractures were observed in all patients at a mean 9.7 months after surgery.

CONCLUSION

The indications of osteosynthesis for stress fractures of the hook of the hamate in baseball players should be carefully considered.

Diagnosis of a hamate hook fracture with 3D reconstruction of computed tomography images: A case report and review of literature

We report the case of a 19-year old man who presented to our institution with a history of pain of one week in the ulnar side of the left wrist and continuous pressing sensation in the palm. According to patient, there was no history of acute hand trauma. The conventional roentgenograms did not show the fracture and computerized tomographic (CT) scanning demonstrated a complete fracture of the hook of the hamate. The patient was given a surgical intervention and the hamate bone was reduced through a palmar skin incision. After surgery, the operated hand was immobilized in a wrist brace and the patient was put on a rehabilitation protocol. At the last follow-up, the patient was able to return to normal living activities without any symptoms. We reviewed the latest articles of the past 18 years and compared the research studies related to the diagnosis and treatment of the hamate hook fracture. Our conclusion is that CT scan is the most effective diagnostic tool for detecting the hamate hook fracture. Three-dimensionally (3D) reconstructed images based of CT could provide more accurate and insight illustration for better evaluation in surgical planning.

[Three-dimensional architecture of intraosseous vascular anatomy of the hamate: a micro-computed tomography study]

OBJECTIVE

To obtain three-dimensional intraosseous artery of the hamate and to provide the vascular anatomy basis of hamate fracture fixation.

METHODS

PbO (lead monoxide, Sinopharm Chemical Reagent Beijing Co. Ltd) was ground into particles less than 40 μm and suspended in turpentine oil (Chemical Reagent Beijing Co. Ltd) at ratios of 1 g : 1.5 mL, 1 g : 1 mL and 1 g : 0.5 mL. Three specimens were investigated. Brachial arteries were cannulated and perfused with lead-based contrast agent. Hamates were harvested and scanned using micro-computed tomography (microCT). The acquisition protocols were as follows: CT scan setup: total rotation [Degrees], 360; rotation steps, 360; X-ray detector setup: transaxial, 2048; axial, 2048; exposure time, 1 500 ms, Binning, 1; system magnification: high-med. X-ray tube setup: 80 kV, 500 mA current. The down-sampling factor used in the reconstruction was 2. The effective voxel size of the final image was 27.30 μm. The three-dimensional model of the hamate was generated and the distribution and pattern of vessels were evaluated.

RESULTS

There were abundant extraosseous vessels around the hamate. They were mainly running in the tendons and ligaments around the hamate. Four vascular zones were identified on the hamate surface. They were on the palmar platform of the hamate body, on the dorsal side, on the ulnar side and on the tip of hamulus, namely. There were anastomoses among 4 vascular zones. We did not observe any vessels penetrating through the articular cartilage. The extraosseous vessels of the vascular zones gave a number of intraosseous branches into the hamate. The hamate body received intraosseous blood supply from the dorsal, palmar and ulnar while the hamulus from the palmar, ulnar and hamulus tip. There were some intraosseous branches anastomosing with each other.

CONCLUSION

The extraosseous and intraosseous vessels of the hamate were more than what used to be considered. The hamate body and hamulus received blood supply from multiple directions and arteries anastomosed extensively both outside and inside the hamate, making it possible that the intraosseous perfusion survived after fracture. It is likely that the nonunion after the hamate fracture is not caused by the vascular damage but the malalignment of the fragments.

A simple method for bone age assessment: the capitohamate planimetry

Objectives

To determine if the capitohamate (CH) planimetry could be a reliable indicator of bone age, and to compare it with Greulich-Pyle (GP) method.

Methods

This retrospective study included 391 children (age, 1–180 months). Two reviewers manually measured the areas of the capitate and hamate on plain radiographs. CH planimetry was defined as the measurement of the sum of areas of the capitate and hamate. Two reviewers independently applied the CH planimetry and GP methods in 109 children whose heights were at the 50th percentile of the growth chart.

Results

There was a strong positive correlation between chronological age and CH planimetry measurement (right, r = 0.9702; left, r = 0.9709). There was no significant difference in accuracy between CH planimetry (84.39–84.46 %) and the GP method (85.15–87.66 %) (p ≥ 0.0867). The interobserver reproducibility of CH planimetry (precision, 4.42 %; 95 % limits of agreement [LOA], −10.5 to 13.4 months) was greater than that of the GP method (precision, 8.45 %; LOA, −29.5 to 21.1 months).

Conclusions

CH planimetry may be a reliable method for bone age assessment.

Key Points

• Bone age assessment is important in the work-up of paediatric endocrine disorders.

• Radiography of the left hand is widely used to estimate bone age.

• Capitatohamate planimetry is a reliable and reproducible method for assessing bone age.

Triquetrohamate Impaction Syndrome: An Unrecognized Cause of Ulnar-Sided Wrist Pain; Its Presentation Further Defined

BACKGROUND

The aim of this review was to further define the clinical condition triquetrohamate (TH) impaction syndrome (THIS), an entity underreported and missed often. Its presentation, physical findings, and treatment are presented.

METHODS

Between 2009 and 2014, 18 patients were diagnosed with THIS. The age, sex, hand involved, activity responsible for symptoms, and defining characteristics were recorded. The physical findings, along with ancillary studies, were reviewed. Delay in diagnosis and misdiagnoses were assessed. Treatment, either conservative or surgical, is presented. Follow-up outcomes are presented.

RESULTS

There were 15 male and 3 females, average age of 42 years. Two-handed sports such as golf and baseball accounted for more than 60% of the cases, and these cases were the only ones that involved the lead nondominant hand, pain predominantly at impact. Delay in diagnosis averaged greater than 7 months, with triangular fibrocartilage (TFCC) and extensor carpi ulnaris (ECU) accounting for more than 50% of misdiagnoses. Physical findings of note included pain over the TH joint, worse with passive dorsiflexion and ulnar deviation. Radiographic findings are described. Instillation of lidocaine with the wrist in radial deviation under fluoroscopic imaging with relief of pain helped to confirm the diagnosis. Conservative treatment was successful in 9 of 18 patients (50%), whereas in the remaining, surgical intervention allowed approximately 80% return to full activities without limitation.

CONCLUSION

Triquetrohamate impaction syndrome remains an underreported and often unrecognized cause of ulnar-sided wrist pain. In this report, the largest series to date, its presentation, defining characteristics, and treatment options are further elucidated.

Conventional chondrosarcoma in the right hand with the invasion of the pisiform and the hamate bones - case report

Chondrosarcoma is a malignant hyaline cartilage forming tumor. It is a rare pathology, with an estimated incidence of one in 200 000 individuals per year. It appears in two forms: primary, representing 90% of all cases and secondary emergence that develops on preexistent lesions. Primary chondrosarcomas are uncommon in the hand, with a frequency of only 1.5-3.2% of all chondrosarcomas. In conventional chondrosarcoma (cCS), the histological malignancy grading represents the main prognostic factor for surgical planning and prognosis. We present the case of a 60-year-old male, examined in the First Department of Orthopedics and Traumatology, "Dr. Pius Branzeu" Clinical Hospital, Timisoara, Romania, with non-specific symptoms in the right hand. After clinical examination and imagistics, surgery and histopathological examination of the tumor were performed. This showed a conventional well differentiated - G1 chondrosarcoma, as suggested also by imagistic and clinical context.

Stress fracture of the hook of the hamate: a case report

Hook of the hamate fractures are uncommon. This fracture is usually seen in sports involving a club or a racquet (i.e., baseball or golf) and is caused by blunt trauma. Stress fractures of the hamate are exceedingly rare. Because of its subcutaneous position and associated soft tissue structures, hook of the hamate fractures can be difficult to diagnosis. When treated early, conservative (non-operative) options can be used to successfully treat the fracture. When the diagnosis is delayed, nonunion of the fracture is common and is usually treated with surgery. This case represents a hook of the hamate stress fracture that healed with casting in spite of being seen two months from the onset of symptoms. Hamate fractures are reviewed, including the anatomy and treatment options for hook of the hamate fractures.

Chondroblastoma with secondary aneurysmal bone cyst of the hamate: case report

Chondroblastoma of the carpals is rare, can mimic other benign bone tumors, and presents a diagnostic challenge. There have been few cases of benign tumors involving the hamate, with only one reported case of chondroblastoma, which was treated with complete hamate excision. We present a case of chondroblastoma with secondary aneurysmal bone cyst of the hamate treated with curettage, high-speed burring, phenol, and autogenous iliac crest bone grafting. At the time of the most recent radiographic follow-up, there was full graft incorporation, preserved hamate morphology, and no evidence of recurrence.

Trans-scaphoid transcapitate transhamate fracture of the wrist: case report

We describe a new pattern of upper limb injury: a combination of fractures of both radius and ulna, with a rare type of trans-scaphoid transcapitate transhamate greater arc injury of the wrist and fractures of metacarpals, managed successfully.

Simultaneous fracture of the waist of the scaphoid and the hook of the hamate

A case of simultaneous fracture of the waist of the scaphoid and the hook of the hamate is presented. The scaphoid fracture was treated surgically with a headless compression screw, while the hook fracture was treated conservatively with cast immobilisation for eight weeks. Both fractures achieved bone union and the patient returned to work without any symptoms or complications. Only two cases of fractures of the scaphoid and hamate have been reported previously. However, both of them involved fracture of the body of the hamate. This is the first report of simultaneous fracture of the scaphoid and the hook of the hamate.

[Anatomic study on hook of hamate bone]

OBJECTIVE

To study the hook of hamate bone by anatomy and iconography methods in order to provide information for the clinical treatment of injuries to the hook of hamate bone and the deep branch of ulnar nerve.

METHODS

Fifty-two upper limb specimens of adult corpses contributed voluntarily were collected, including 40 antisepticized old specimens and 12 fresh ones. The hook of hamate bone and its adjacent structure were observed. Twenty-four upper limbs selected randomly from specimens of corpses and 24 upper limbs from 12 healthy adults were investigated by computed tomography (CT) three-dimensional reconstruction, and then related data were measured. The measurement results of 24 specimens were analyzed statistically.

RESULTS

The hook of hamate bone is an important component of ulnar carpal canal and carpal canal, and the deep branch of ulnar nerve is located closely in the inner front of the hook of hamate bone. The flexor tendons of the forth and the little fingers are in the innermost side, closely lie next to the outside of the hook of hamate bone. The hamate bone located between the capitate bone and the three-cornered bone with wedge-shaped. The medial-, lateral-, and front-sides are all facies articularis. The hook of hamate bone has an approximate shape of a flat plate. The position migrated from the body of the hamate bone, the middle of the hook and the enlargement of the top of the hook were given the names of "the basis of the hook", "the waist of the hook", and "the coronal of the hook", respectively. The short path of the basement are all longer than the short path of the waist. The long path of the top of the hook is the maximum length diameter of the hook of hamate bone, and is longer than the long path of the basement and the long path of the waist. The iconography shape and trait of the hook of hamate bone is similar to the anatomy result. There were no statistically significant differences (P > 0.05) between two methods in the seven parameters as follows: the long path of the basement of the hook, the short path of the basement of the hook, the long path of the waist of the hook, the short path of the waist of the hook, the long path of the top of the hook, the height of the hook, of hamate bone, and the distance between the top and the waist of the hook.

CONCLUSION

The hook of hamate bone can be divided into three parts: the coronal part, the waist part, and the basal part; fracture of the hamate bone can be divided into fracture of the body, fracture of the hook, and fracture of the body and the hook. Fracture of the hook of hamate bone or fracture union can easily result in injure of the deep branch of ulnar nerve and the flexor tendons of the forth and the little fingers. The measurement results of CT three-dimensional reconstruction can be used as reference value directly in clinical treatments.

Midcarpal instability: a diagnostic role for dynamic ultrasound?

PURPOSE

The aim of this study was to describe the technique of dynamic ultrasound (US) examination of the triquetral clunk, and to illustrate the range of findings in four patients with midcarpal instability (MCI).

MATERIALS AND METHODS

Four patients were identified (3 men, 1 woman). The case notes, plain radiographs, MRI and dynamic US for each patient were reviewed. Digital video files recording the dynamic US of the triquetral clunks were analysed for the following features of abnormal triquetral mobility: direction and speed of triquetral snap, amount of anteroposterior translocation, and flexion or extension during the snap.

RESULTS

Five different triquetral clunks were recorded in 4 patients. In four out of five cases the clunk occurred during ulnar translocation of the wrist, and in one during radial translocation. Anteroposterior translocation was anterior (3.4 - 4.7 mm) in three of the clunks and posterior (1 - 10 mm) in two. The degree of flexion or extension varied between 1 and 16 degrees . The snapping phase of the clunk lasted between 0.17 and 0.25 seconds.

CONCLUSION

Dynamic US can be used to confirm the diagnosis of midcarpal instability by identifying a triquetral catch-up clunk. Quantification of carpal mobility with US may lead to further insights into the mechanics of MCI.

Haematogenous pseudomonas osteomyelitis of the hamate--treatment by radical debridement and bone grafting

A case of isolated chronic osteomyelitis of the hamate bone in a 13-year-old boy, who presented with a sinus on the dorsum of the hand, is reported. Radiological examination revealed multiple marginal and intra-osseous lytic areas with sclerotic rims in the hamate and at the fourth and fifth metacarpal bases. He was treated with excision of the sinus, curettage of the hamate lesion and hamato-metacarpal fusion which provided satisfactory control of infection while salvaging the function of the affected hand.

Aktuelle Behandlung der Hamulus ossis hamati-Fraktur

PURPOSE

Hamate hook fractures can be treated conservatively or surgically, whereby fragment and fracture position, age of the fracture, associated injuries, and individual needs of the patient all influence the choice of the therapeutic procedure. Acute non-displaced fractures are frequently treated conservatively, while displaced fractures and nonunions undergo surgical treatment. We report our experience in diagnostic and therapeutic management of 14 hamate hook fractures. CLINICAL MATERIAL AND METHOD: During a three-year period, 14 patients (eleven men and three women) 21 to 73 years old (42.0 +/- 17.9 years) with fractures at the base of the hamate hook were treated at three hand surgery units. The retrospective study of all patients included a chart review, postoperative radiological imaging after one year, and clinical examinations with grip strength measurements after 18 to 34 months (27.8 +/- 4.9 months). In six patients (43 %), the acute fracture was immobilized in a lower arm cast for six weeks, while eight patients (57 %) were operated primarily. In five cases (36 %) excision of the fragment and in three cases (21 %) open reduction and internal fixation using a screw were performed. Of six patients treated conservatively, five developed nonunion after two to five months (3.0 +/- 1.2 months) with persistent pain and underwent secondary surgery. One patient was asymptomatic despite a nonunion and declined surgical treatment. In three cases the fragment was excised, while two patients underwent open reduction and internal fixation with a screw.

RESULTS

All patients operated primarily were free of complaints three months after surgery. The success rate of surgical treatment (8/8) was therefore significantly higher than that after conservative treatment (1/6).

CONCLUSION

Compared to conservative treatment of acute non-displaced hamate hook fractures, which is associated with a high risk of developing symptomatic nonunion, primary surgical treatment reliably yields a good clinical outcome. Here, results after fragment excision and open reduction and internal fixation are comparable.

Optimierung von konventionellen Röntgenaufnahmen zur Erkennung von Hamulus ossis hamati Frakturen

Fractures of the hook of the hamate are a rare event. The fracture cannot always be detected clinically and standard radiographs do not always provide an overlap-free image of the hook of the hamate, so that fractures can easily be overlooked. The objective of the present study was to examine if the sensitivity of detecting hamulus ossis hamati fractures can further be improved by a modified conventional radiographic projection. After dissection of the hook of the hamate on 10 cadaver hands, a fracture was produced close to the base using a surgical chisel. Conventional radiographs were then performed in four different projections (dorso-palmar, lateral, carpal-tunnel and oblique view). The oblique view was obtained in a 45 degrees supination position, slight extension and radial duction, with the tube tilted from distal to proximal by 30 degrees. An axial spiral CT was used as a reference for detection of the fracture. The highest sensitivity of the conventional radiographs, with 8/10 identified fractures (80%), was achieved by the oblique view. The carpal-tunnel view with 4/10 (40%) and the dorso-palmar projection with 3/10 (30%) were much lower. All fractures were missed in the lateral projection. If all of the conventional radiographic projections are taken into account, the sensitivity is increased to 90%. All of the fractures were reliably detected in the axial CT-image. If a hamulus ossis hamati fracture is suspected clinically, in addition to the dorso-palmar and carpal-tunnel view, the special oblique view described here should be performed as a third projection plane, while the lateral view can be dispensed with. However, even if all projections are taken into account, a negative finding in the conventional radiographic imaging does not exclude a fracture with absolute certainty. In such cases, a CT or MRI should be performed to exclude a fracture.

Population variation in the incidence of the medial (hamate) facet of the carpal bone lunate

Studies on the wrist joint have shown two types of the carpal bone lunate. In type II lunate there is a facet on the medial side of the lunate for articulation with the proximal pole of the hamate; such a facet is absent in type I lunate. Type II lunates have different kinematics, are more prone to clinically relevant degenerative changes in the hamato-lunate joint and are an uncommon cause of ulnar-sided wrist pain. Ninety plain radiographs showing postero-anterior views of the wrist (52 right and 38 left wrists) were studied in a population of Malays from Malaysia (mean age 48 years; age range 23 to 67 years) to determine the incidence of type I and type II lunates. Our findings were compared with those in other reports in the literature. In Malays, only 24 wrists (26.7%) showed a type II lunate compared to a reported incidence of 50% or more in populations from the Western world. Such a low incidence of type II lunate has not been reported before and may represent a genetic variation in Malays. Consequently, osteoarthritis of the hamate or lunate may play a less significant role in causing ulnar-sided wrist pain in Malays. In conclusion, the prevalence of type II lunate might vary in different population groups and further studies could be necessary to confirm this observation.

Pisiform and hamate coalition: case report and review of literature

Pisiform and hamate coalition is a rare anomaly of the carpal bones; a symptomatic case is an especially rare condition. We report a case of symptomatic pisiform and hamate coalition in a 15-year-old Japanese male. The literature of pisiform and hamate coalition is reviewed.

The hamate facet of the lunate: a radiographic study in an Arab population from Bahrain

Based on the presence of a facet for the hamate two types of lunate bone have been described in the wrist; type I is without a facet for the hamate while type II bears a facet on the medial surface for articulation with the proximal pole of the hamate. Compared to type I lunates, type II lunates have been shown to have different kinematics, are more prone to clinically relevant degenerative changes in the hamato-lunate joint and may cause ulnar-sided wrist pain. The incidence of type II lunates seems to vary in different populations. Postero-anterior (PA) view of plain radiographs of the hand was studied in Arab subjects from Bahrain (n=381; 307 males and 74 females) to determine the incidence of type I and type II lunates. The mean age of the subjects was 31.1 years, the range being 18-80 years. In the population studied, only 148 (38.8%) of the 381 wrists showed type II lunate; 121 (31.7%) were found in males and 27 (7.1%) in females. There was no significant difference in the mean age of subjects with type I or type II lunates (P=0.16). There was no correlation between side and gender with the presence or absence of a hamate facet on the lunate. The incidence of type II lunate was much lower than reports in the literature of populations from the Western world, which could be attributed to a genetic variation in the Arab population in Bahrain. These data indicate that osteoarthritis of the hamate or lunate is less likely to be a cause of ulnar-sided wrist pain in Bahraini Arabs.

Anatomic variations of the hook of hamate and the relationship to carpal tunnel syndrome

PURPOSE

To determine the incidence of anatomic variations of the hook of hamate and to evaluate its association with the development of carpal tunnel syndrome (CTS).

METHODS

Radiographs of 3,218 hands (2,070 patients) were evaluated. This group included 2,866 hands diagnosed with CTS and 352 hands without the diagnosis of CTS. Using the carpal tunnel view variations of the hook of hamate were identified. Variants were classified based on appearance and measurements. Patients having variant hooks of hamate who were diagnosed with CTS then were compared with patients with variant hooks of hamate who had no evidence of CTS. Endoscopic carpal tunnel release using the Chow technique was performed on all patients with CTS who had a known variation of the hook of hamate without difficulty or complication.

RESULTS

Variations of the hook of hamate were found in 96 hands: 42, bipartite hook; 50, hypoplastic hook; and 4, aplastic hook. Ninety-three hands with variant hooks of hamate were diagnosed with CTS. The remaining 3 hands identified with variants had no evidence of CTS. After comparing the 2 groups, we found that the incidence of a variant hook of hamate in the group with CTS was significantly greater than the incidence of variations in the group without CTS.

CONCLUSIONS

Three variations of the hook of hamate were identified with radiographic evaluation using the carpal tunnel view. Variations are more prevalent than once thought. There was a significant increase in the incidence of variation in the hook of hamate in the group with CTS compared with the group without CTS.

Therapeutic Alternatives in Nonunion of Hamate Hook Fractures

Symptomatic nonunion frequently results after conservative treatment of hamate hook fractures, emphasizing the need of appropriate surgical strategies. A retrospective analysis of 8 patients with nonunions treated by fragment excision or open reduction and internal fixation (ORIF) at 3 centers was performed. The literature was reviewed for treatment options, as bone grafting and low-intensity pulsed ultrasound. Although fragment excision is advocated as the "gold standard" in nonunion, reports on functional results are controversial, and recent anatomic and biomechanical studies of the hook challenge this opinion. In our patients, complete relief of symptoms and comparable functional results were observed after ORIF or fragment excision. Bone grafting could supplement ORIF in selected cases. Low-intensity pulsed ultrasound may evolve as a conservative treatment option. Several alternatives to hook excision are available aiming at complete anatomic and functional recovery of hamate hook nonunion. Further experience is needed before general recommendations can be formulated.